Second Amendment issues are pretty much the opposite; intensely ideological, deeply rooted in the philosophy of how participatory democracy is supposed to work.  

The Venn diagram of "Unanimous SCOTUS decisions" and "2nd Amendment cases" was pretty much a perfect figure 8...

...until this week.   

The Supreme Court ruled unanimously last Thursday on a suit by the Mexican government against gun manufacturers whose products wound up in the hands of the cartels that the Mexican government basically lets roam free in the first place. 

In 2021 the Mexican government filed a lawsuit in a Massachusetts federal court against seven major U.S. gun makers and one gun wholesaler. It contended that gun makers design and market their guns as military-style weapons, knowing that doing so makes them more attractive to drug cartels in Mexico. The gun makers also use a three-tier distribution system, Mexico alleged, that facilitates an illegal market for their guns in Mexico, with gun makers selling to wholesale distributors, who then sell to retail dealers, and gun dealers then sell the guns to “straw purchasers” – buyers who were acting as a front for someone else who could not legally purchase a gun.

So to sum up; the plaintiff was apparently suing the manufacturers for not being able to predict which guns will go, by countless means, legal and (mostly) illegal, to illegal users in a country that simultaneously has incredibly restrictive gun laws...:

Mexico itself has very stringent gun laws, making it virtually impossible for cartels to obtain guns legally there. The country has just one gun store and “issues fewer than 50 gun permits each year.” Despite its efforts to strictly regulate guns, however, Mexico ranks third in the world in the number of gun-related deaths. And in particular, the Mexican government says, as many as 70% to 90% of the guns that police recover at crime scenes in that country were trafficked into Mexico from the United States.

...and a criminal culture that operates, armed up like a good-size military, in the open and with complete impunity.  

It's not a surprise that Republicans in Congress supported the defense:

"I am leading this amicus brief to uphold American sovereignty and our Second Amendment. The lawsuit filed by Mexico seeks to trample on our Constitution," Cruz told Fox News Digital. "I look forward to the Supreme Court ending this madness, putting an end to Mexico’s assault on our Second Amendment, and sending a clear message that American sovereignty will not be eroded by any country."

Sens. Marsha Blackburn, R-Tenn.; Mike Braun, R-Ind.; Bill Cassidy, R-La.; John Cornyn, R-Texas; and Rick Scott, R-Fla., are just several Senate members joining Cruz in filing the brief. Reps. Darrell Issa, R-Calif.; Clay Higgins, R-La.; Pete Sessions, R-Texas; and Claudia Tenney, R-N.Y., have also joined Cruz's brief.

But when you've got the absurdity of it all being called out, not by Clarence Thomas or Samuel Alito, but by Justice Kagan, you know you're approaching real-life parody:

"Mexico’s complaint, for the reasons given, does not plausibly allege such aiding and abetting," Kagan wrote. "So this suit remains subject to PLCAA’s general bar: An action cannot be brought against a manufacturer if, like Mexico’s, it is founded on a third party’s criminal use of the company’s product."

The Supreme Court concluded that the "proximate cause" standard meant the U.S. manufacturers could not be sued when the complex commerce pipeline goes from them to wholesalers, distributors, rogue retail dealers, straw purchasers, smugglers and then to the Mexican cartels.

The decision is the latest in a decent, not great, term in the SCOTUS for 2nd Amendment activists.